Shaggy heads and dark roots have turned out to be an unexpected symptom of the COVID-19 pandemic.

So it was a relief for many Mainers to hear Gov. Mills announce last month that barbershops, hair salons and even pet groomers would be among the first public-facing businesses to reopen under her modified stay-at-home order.

Good news travels fast, so it should not come as a surprise that people who cut hair in the communities near Maine’s southern border are getting interest from residents of other states, where rules haven’t been lifted yet. A provocative headline on a digital Boston Globe article offered the invitation “Let’s sneak away to Maine for haircuts.”

“Sneak” is the right word. Since Maine requires out-of-state visitors to quarantine for 14 days before coming into contact with anyone here, most of these border crossers would be breaking the law.

Hopefully, the word will get out that Maine barbers and stylists are turning these customers down, even checking IDs to make sure that only locals are getting into their chairs. But the experience of southern Maine barbers provides an important lesson as other parts of the state economy reopen.

A virus doesn’t respect state boundaries, and Maine can’t afford to get too far ahead of the region. The COVID-19 crisis is far from over, and the sacrifices made by Mainers over the last few months could be quickly erased if we are not careful.

Through a combination of luck and timely regulation, Maine has avoided the worst possible outcomes of the coronavirus pandemic so far, maintaining lower infection rates and fewer deaths relative to population than other Northeastern states. Our health care system has not been overwhelmed. We have flattened the curve.

But that means that most of us have never been exposed to a highly contagious virus to which we have no immunity. It wouldn’t take much to spark a brushfire of exponential growth here if we were to stop being careful.

Something to think about when people call to reopen the economy is what that would mean for parts of Maine that are destinations for out-of-state visitors. Kittery is just about a half-hour drive from the border of Massachusetts, where there have been nearly 80,000 confirmed COVID-19 cases and more than 5,000 deaths. In Connecticut, where the barbershops and hairstylists are still closed, there have been more than 33,000 COVID cases and 3,000 deaths.

A five-hour drive from New York City, where there have been 338,000 cases and 21,000 deaths, might sound too far to go for a haircut, but it’s not too far for some. If Maine starts opening restaurants, hotels and retail businesses much sooner than its neighbors in the region, we can expect to attract refugees from coronavirus hot spots who are tired of living under their own state’s public health regulations.

What’s happening with barbers and stylists offers a good view into how this process might work if Maine opens up its businesses much more quickly than neighboring states are.

People will ignore our quarantine requirement if they think that they can get something here that’s not available to them at home. The strength of our regulations relative to those of other states – and how strictly they are enforced – will play a big role in whether Maine succeeds in fighting this pandemic.